Conspicuous void: The always near-empty pedestrian walkways have sucked the life out of Broadway above Times Square. Photo: Robert Miller

After two years of public si lence, prominent Midtown business owners are speak ing out over the ruinous impact of the 12-block-long pedestrian and bike lanes on Broadway north of 47th Street.

David Letterman ridiculed the result as a “petting zoo” for tourists — but owners of theaters, stores and restaurants held their tongues before the media. Fearful of retribution from Mayor Bloomberg’s agency commissars, they would only privately fume over the Department of Transportation’s destructive tampering with the urban fabric.

But the pain’s grown too strong. Now, in guarded but passionate terms, Broadway entrepreneurs talk of lost business they may never be able to recoup.

The Broadway pedestrian and bike lanes from West 47th Street to Columbus Circle are irrefutable evidence of the DOT’s failure to respect a basic fact of city life: People want to be on the sidewalk near stores, restaurants and building entrances — not in the middle of the road.

While the DOT’s Times Square “plazas” are popular with burger-chomping tourists, the Broadway lanes to the north — as wide as 20 feet at some points — are universally shunned.

In a 15-minute stroll from end to end of the strip yesterday, when Midtown teemed with office workers and sightseers, I counted a mere seven bikers and five walkers using the lanes.

The resulting estrangement of the east-blockfront sidewalk from the rest of Broadway has been catastrophic both for mom-and-pop stores and for some of the city’s most famous institutions. None would quantify the impact in terms of dollars, but their thrust was clear.

Broadway Association chief Cristyne Nicholas — whose organization promotes the interests of many area businesses as well as theater owners — states, “Our members have complained that it’s confusing and has a negative impact on their business.

“It has been a deterrent to both pedestrian and vehicular traffic because the lane makes it look isolated.”

Caroline Hirsch, owner of legendary Caroline’s comedy club at Broadway and 49th Street, says, “It’s changed every rhythm on that street. My weekend business is totally off because of it.”

She notes that “Broadway, this fabulous street, now has trees in the middle of it. It’s impossible to navigate” — a fact that makes New York City’s single most iconic thoroughfare forbidding to strollers as well as to drivers, who now prefer not to come to the area at all. (Cars can park in mid-Broadway bays — if drivers can figure out how).

Stephen Hanson is the president of B.R. Guest, the restaurant company that owns Ruby Foo’s at Broadway at 49th Street. He says, “It’s hurt our business there tremendously. There’s no walk-by traffic we used to have at night, because everybody’s in a mad dash to get to the central arcade area.”

Hanson says his Blue Fin at 47th Street has benefited from the Times Square plazas — but that their popularity, combined with the inhospitability of the bike/pedestrian lane to the north, sucked the energy out of Broadway above 47th Street — “anything for 10 blocks up is getting a vacuum effect,” he said.

Managers of Serafina and Brasserie Cognac near 55th Street who didn’t wish to be named similarly said the lanes have reduced the number of customers. One noted that the city is so enamored of the little-used lanes that clean-up crews arrive at 1 a.m. to hose down the green-painted pedestrian lane for no good reason.

At first glance, the DOT’s decision to turn much of 12 once-vibrant blocks into a wasteland seems mere stupidity. In fact, it served a purpose — namely, thinning Broadway’s four lanes of vehicular traffic to two (and to one in certain spots).

DOT Commissioner Janette Sadik-Khan — who’s finally taking flak for her destructive measures in all five boroughs — hates Broadway for slicing through the street grid at an angle and generating what she regards as intolerable congestion.

But what’s indefensible is the ruination of Broadway’s heart. Sadik-Khan has little taste for the street energy that helped make New York the world’s most dynamic (and economically potent) city; her priorities lie in the cyclist-heaven Copenhagen of her urban-phobic imagination.

Bloomberg, no cyclist himself, humors her because her schemes coincide with his own anti-congestion agenda. The cost to everyone else has yet to be tallied. But he might, for starters, listen to what Broadway’s merchants have to say.